Facies arachn 

 darae matris 



Plexus endoly 



Saccus 

 endolymph. 



Art. 



Sinus dur. matr. 

 transversus 



educt. vestlb. 



Fig. 6 Section through the endolymphatic sac showing its relation to the dura 

 and blood vessels in a human fetus measuring 240 mm. crown-rump length 

 (No. 1131, Carnegie Collection). Endolymphatic sac is stippled dark. Blood 

 vessels are shown in plain white. The endolymphatic plexus is more dense on 

 the median or upper surface of the sac; on the lateral or lower surface the plexus 

 is partly replaced by the main channel through which it drains into the trans- 

 verse sinus. 'V. d.,' a large dural vein; 'Art.,' arter}'. The arachnoidal surface 

 of the dura is intact, but the bony surface was torn in the removal of the specimen 

 from the bone. Enlarged 15 diameters. 



■ ^ 86 



